This invention relates to a jump rope and particularly to a jump rope having relatively rigid handles secured to the opposite ends of the rope.
Jump ropes have for many years been used both as toys by children and as exercise devices by persons interested in physical fitness, particularly with the relatively substantial increased interest in physical fitness. Competitive jumping is now also common. Jump rope construction has become more complex and sophisticated, particularly with an increasing demand by competitive jumpers for greater rapidity of rope rotation, flexibility of movement and ease of movement. Frictional forces involved in the connection of the flexible rope to the handle structures held by the jumper are a particular area of interest which has received significant attention. The frictional forces created at the connection of the rope to the handle restricts the rotational speed and of course creates a load on the person's arm. The handle connection also constitutes a principle source of wear on the rope, requiring frequent replacement. Professional type jump ropes are generally relatively costly.
Adults involved in personal fitness often subject jump ropes to strenuous jumping conditions. In addition, experts and professional jumpers who jump competitively of course require the highest quality jump rope. As a result, rather sophisticated systems have been developed for connecting of a rope to a rigid handle.
U.S. Pat. No. 4,179,119 which issued Dec. 18, 1979 discloses a skipping rope having a tubular wooden handle with the interior forming an elongated axial journal or sleeve bearing. A rotatable rod is journaled in the tubular handle and extends outwardly thereof to form a peg protruding from the handle. The peg has a plurality of transverse openings for coupling of the rope to the peg. The patent describes other prior art rigid connection to the handle and the creation of a high stress point resulting in a premature destruction of the rope which is avoided by the structure disclosed in the patent. In use, as the rope rotates, the rod rotates within the elongated sleeve bearing. Other special structures have also been suggested. A spring-loaded ball bearing unit is disclosed in U.S. Pat. No. 4,330,118 which issued May 18, 1982. In the latter patent, the handle is formed with a tubular cup shaped conical fastener which protrudes from the rope end of the handle. A plurality of ball elements are uniformly spaced within the conical fastener and held in place by a spring-loaded retainer. Still other patents have shown special structures and connections of jumping rope for other purposes or reasons. For example, U.S. Pat. No. 438,489 which issued in 1890 discloses a musical skipping rope having a conventional clapper arrangement in which the handle is connected by an offset ratcheting noise making mechanism. The ratchet wheel is secured to the handle and with the ratchet arm extending at right angles therefrom and with the jump rope being interconnected to the ratchet arm by a transverse coupling. Hoop-type jumping toys are shown for example in U.S. Pat. No. 2,039,731 and 4,049,264. Jump ropes with various other forms of interconnection are additionally shown in U.S. Pat. Nos. 4,093,211, 1,371,915, 2,253,075, 4,136,866, 4,157,827, 4,177,985, 4,201,382, 4,375,886, 4,385,759, 4,293,125, 3,554,539, 3,958,802, 4,135,713, and 4,192,501.
There is a continuing demand for increasing the rotational speed of the jump rope without creating undue loads on the connection of the rope and handle and without increasing the load on the jumper. The prior art devices which are all directed to certain aspects of the jump rope connection still include interconnections which involve an undesirable amount of frictional forces, particularly when a change in the jumping motion is created; for example, changes from the conventional simple straightforward loop movement about the body to a criss-crossing of the rope during the formation of the loop and the like.
Notwithstanding the extensive development over the years in the handle structures for jump ropes, there remains a substantial demand and need for a more reliable and long-life handle structure.